Floor mats of the type with which this invention is concerned are widely used as protective cover for carpets and the like. Such mats are typically placed in high traffic areas to protect underlying carpet, or in high load areas such as under a movable desk chair to facilitate rolling movement of the chair, or in a motor vehicle under the driver's feet. These mats are commonly made of vinyl or polyvinyl chloride (PVC).
The underside of a floor mat includes a multiplicity of cleats or grippers extending downward to engage the underlying carpet to thereby restrain the mat against slipping and sliding on the carpet. The grippers that I know of in the prior art are of hemispherical, or pyramidical, or convex conoidal, or cylindrical configuration. These prior art configurations are illustrated, left to right respectively, in FIG. 3.